“I like large parties. They’re so intimate.” — Jordan Baker, “The Great Gatsby”

One could argue that few fashion items are more intimate than a party dress, particularly when the soiree is fancy and large. No other piece reflects more acutely the thought, planning, emotion — mental torment included — one’s sartorial choices can involve.

Miuccia Prada’s cerebral approach to fashion (along with her spectacular body of work) may have been one reason Baz Luhrmann and costume designer Catherine Martin sought her collaboration on “The Great Gatsby.”

“When I read it, it was psychological. It was not about glamour for me,” Prada told WWD of her most recent reading of the novel. “It was a real [study of] personality, very internalized.”

Luhrmann’s much-anticipated film adaptation of the famed tragedy by F. Scott Fitzgerald premieres on Wednesday at Lincoln Center. An exhibit of the Prada-Martin costumes opens tonight at the brand’s SoHo flagship and runs through May 12 before heading to Tokyo.

Without the designer’s knowledge, Martin used existing Prada and Miu Miu looks for one of the film’s tests. These worked so well in capturing Gatsby’s tony decadence that Martin asked Prada to participate in the film itself. Unlike Brooks Brothers, which supplied all of the primary men’s clothes and 600 background suits, Prada contributed 40 looks for the film’s two party scenes. RELATED STORY: Brooks Brothers to Launch Gatsby Line >>

The two women agreed upon the need to evoke the Twenties, specifically, without getting mired in what Martin calls “historical pedantry.” She maintains that rigid adherence to historical minutia can impede the modern audience’s appreciation of a story. That said, Martin was quick to defend whatever license was taken. “The reality is that from 1920, I could find a photo or a fashion illustration that would support almost any choice that we’ve made in the film. But we are not making a documentary. We are trying to express a story in a way in which Fitzgerald’s visceral modernity is able to transgress the plane of the screen.”

Martin delved again into recent Prada and Miu Miu collections and came away with a trove of possibilities. The fashion designer was “relieved” to have so ample a starting point. These included the “chandelier dress” from Prada spring 2010, which Martin ultimately chose as Daisy’s party dress. Unlike the looks shown here, this one has been seen widely in the film’s trailer and publicity stills. “It was meant to be about light,” Prada said, adding that for the film, “it became about money, because [Luhrmann] wanted to show her as the most beautiful and rich woman on earth.”

Asked if she’d been conscious of a recurring Twenties mood in her work, Prada offered a quick denial. “The fact is, I had not,” she mused, intrigued by how clothes designed for a sophisticated 21st century clientele could transcend nearly 100 years of time. “That’s what’s interesting. The point of view can transform things so much. Yes, probably a few [dresses] had that kind of edge, but almost none were meant to be the Twenties when I did them. I was really fascinated by that.”